Effect of fullerenes on the sliding movement of actomyosin complex

Matsui, M., Hatori, K.

Department of Bio-System Engineering, Yamagata University



Abstract
Fullerenes that are composed entirely of carbon are expected to apply for biomedical fields, as fullerenes possess the specific structure, conductivity and reactivity. The effects of fullerenes on the cell functions have been investigated so far. It has been shown that fullerenes act as a scavenger against reactive oxygen species. In order to examine whether these fullerenes influence the properties of proteins underlying cell functions, we employed the actomyosin complexes as model molecules, which would be capable of the enzymatic activity, self-assembly and motile activity. In the present study, we chose two kinds of fullerenes, namely Buckminsterfullerene C60 and fullerenol C60-(OH)12. These specific hollow spheres in size of 0.7 nm, which is the intermediate size between smaller compounds and proteins, may be caught in the pockets on protein surface. The sliding velocity of actin filaments on myosin molecules was examined in the presence of fullerenes. The velocity of filaments decreased to about 80 % as fullerenol concentration was increased up to 0.015 mM. In contrast, the velocity slightly increased with the increase of concentration of C60. Furthermore, addition of C60 in the polymerization process from actin monomers into the filaments markedly suppressed the formation of filament. The present results show the different effects of sphere-shaped fullerenes on the motile activity of actomyosin complex, in respond to the hydrophilicity on fullerene surface.